PRECISION SMALL-SIZED NULL THERMOSTAT Russian patent published in 2003 - IPC

FIELD: measurement technology, specifically, devices for thermostatting of test junctions of differential thermocouples. SUBSTANCE: null thermostat comprises external cylindrical chamber made of material displaying high thermal conductivity. Thermoelectric module is linked to upper base on inner side by means of hot junction. Cold junction of thermoelectric module is in good contact with cylindrical chamber. Chamber houses distilled water divided by phase boundary into solid and liquid phases. Ring-shaped float fabricated from water non-wettable material freely floats in liquid phase. Test junction of thermocouple that should be kept at temperature of 0 C is located in center of float. Leads of test junction of thermocouple are brought out of thermostat through special seal. Test junction of thermocouple is anchored in center of float with the help of two thin capron threads which ends cross and are fixed in center of float. EFFECT: raised thermostatting precision of test junctions of differential thermocouples. 2 dwg